Various raw materials such as crude oil are mixtures of various materials, for example, various compounds, and the raw materials may be usually used after being separated into each compound. A representative process from among chemical processes for separating the mixture is a distillation process.
For example, the mixture may pass through one or more distillation columns and be distilled, a part or all of the stream in the distillation process may pass through a condenser or a reboiler, and then flow back to the distillation column, and a high-purity compound may be obtained through the process. It is common that in the case of a typical distillation column, a raw material or reflux stream is introduced in one direction, or a product stream also flows out in one direction only. However, when a raw material to be introduced into the distillation column is supplied in one direction only, a liquid to drop onto the lower part area of plates into which the raw material is introduced does not evenly drop, so that channeling may occur. Further, the liquid likewise drops unevenly even when the stream discharged from the distillation column flows back in one direction. In this case, unnecessary energy may be consumed in order to maintain the concentration of each stream.